The energy consumption for all these countries is aggregated by fuel and end-uses and a share is applied to the total consumption by fuel from Eurostat. This method guarantees the coherence between the aggregate and disaggregated energy consumption.

For instance, for space heating, the consumption of gas is calculated as the total consumption of gas as published by Eurostat for the EU-27 multiplied by the share of space heating in the gas consumption in the sample of 16 countries. The space heating consumption for the EU-27 is then calculated as the sum of the consumption for space heating for each fuel.